/*
 * This file is part of espanso.
 *
 * Copyright (C) 2019-2021 Federico Terzi
 *
 * espanso is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * espanso is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with espanso.  If not, see <https://www.gnu.org/licenses/>.
 */

use std::thread::JoinHandle;

use crate::path::Paths;
use anyhow::Result;
use crossbeam::channel::Receiver;
use espanso_clipboard::ClipboardOptions;
use espanso_config::{config::ConfigStore, matches::store::MatchStore};
use espanso_detect::SourceCreationOptions;
use espanso_engine::event::{EventType, ExitMode};
use espanso_inject::{InjectorCreationOptions, KeyboardStateProvider};
use espanso_ui::{event::UIEvent, UIRemote};
use log::{debug, error, info, warn};

use crate::{
    cli::worker::{
        context::Context,
        engine::{
            dispatch::executor::{
                clipboard_injector::ClipboardInjectorAdapter,
                context_menu::ContextMenuHandlerAdapter, event_injector::EventInjectorAdapter,
                icon::IconHandlerAdapter, key_injector::KeyInjectorAdapter,
                secure_input::SecureInputManagerAdapter, text_ui::TextUIHandlerAdapter,
            },
            process::middleware::{
                image_resolve::PathProviderAdapter,
                match_select::MatchSelectorAdapter,
                matcher::{
                    convert::MatchConverter,
                    regex::{RegexMatcherAdapter, RegexMatcherAdapterOptions},
                    rolling::{RollingMatcherAdapter, RollingMatcherAdapterOptions},
                },
                multiplex::MultiplexAdapter,
                open_config::ConfigPathProviderAdapter,
                render::{
                    extension::{
                        choice::ChoiceSelectorAdapter, clipboard::ClipboardAdapter,
                        form::FormProviderAdapter,
                    },
                    RendererAdapter,
                },
            },
        },
        match_cache::{CombinedMatchCache, MatchCache},
        ui::notification::NotificationManager,
    },
    common_flags::{
        WORKER_START_REASON_CONFIG_CHANGED, WORKER_START_REASON_KEYBOARD_LAYOUT_CHANGED,
        WORKER_START_REASON_MANUAL,
    },
    preferences::Preferences,
};

use super::secure_input::SecureInputEvent;

mod caches;
pub mod dispatch;
pub mod funnel;
mod keyboard_layout_util;
pub mod process;

#[allow(clippy::too_many_arguments)]
pub fn initialize_and_spawn(
    paths: Paths,
    config_store: Box<dyn ConfigStore>,
    match_store: Box<dyn MatchStore>,
    ui_remote: Box<dyn UIRemote>,
    exit_signal: Receiver<ExitMode>,
    ui_event_receiver: Receiver<UIEvent>,
    secure_input_receiver: Receiver<SecureInputEvent>,
    use_evdev_backend: bool,
    start_reason: Option<String>,
    ipc_event_receiver: Receiver<EventType>,
) -> Result<JoinHandle<ExitMode>> {
    let handle = std::thread::Builder::new()
        .name("engine thread".to_string())
        .spawn(move || {
            // TODO: properly order the initializations if necessary
            let preferences = crate::preferences::get_default(&paths.runtime)
                .expect("unable to load preferences");

            let app_info_provider =
                espanso_info::get_provider().expect("unable to initialize app info provider");
            // TODO: read interval from configs?
            let cached_app_info_provider = caches::app_info_provider::CachedAppInfoProvider::from(
                &*app_info_provider,
                std::time::Duration::from_millis(400),
            );
            let config_manager = super::config::ConfigManager::new(
                &*config_store,
                &*match_store,
                &cached_app_info_provider,
            );
            let match_cache = MatchCache::load(&*config_store, &*match_store);
            let default_config = &*config_manager.default();

            let modulo_manager = crate::gui::modulo::manager::ModuloManager::new();
            let modulo_form_ui =
                crate::gui::modulo::form::ModuloFormUI::new(&modulo_manager, &config_manager);
            let modulo_search_ui =
                crate::gui::modulo::search::ModuloSearchUI::new(&modulo_manager, &config_manager);
            let modulo_text_ui = crate::gui::modulo::textview::ModuloTextUI::new(&modulo_manager);

            let context: Box<dyn Context> = Box::new(super::context::DefaultContext::new(
                &config_manager,
                &cached_app_info_provider,
            ));
            let builtin_matches = super::builtin::get_builtin_matches(&*config_manager.default());
            let combined_match_cache = CombinedMatchCache::load(&match_cache, &builtin_matches);

            let match_converter =
                MatchConverter::new(&*config_store, &*match_store, &builtin_matches);

            let has_granted_capabilities = grant_linux_capabilities(use_evdev_backend);

            // TODO: pass all the options
            let (detect_source, modifier_state_store, sequencer, key_state_store) =
                super::engine::funnel::init_and_spawn(SourceCreationOptions {
                    use_evdev: use_evdev_backend,
                    evdev_keyboard_rmlvo: keyboard_layout_util::generate_detect_rmlvo(
                        &*config_manager.default(),
                    ),
                    hotkeys: match_converter.get_hotkeys(),
                    win32_exclude_orphan_events: default_config.win32_exclude_orphan_events(),
                    win32_keyboard_layout_cache_interval: default_config
                        .win32_keyboard_layout_cache_interval(),
                })
                .expect("failed to initialize detector module");
            let exit_source = super::engine::funnel::exit::ExitSource::new(exit_signal, &sequencer);
            let ipc_event_source =
                super::engine::funnel::ipc::IpcEventSource::new(ipc_event_receiver, &sequencer);
            let ui_source = super::engine::funnel::ui::UISource::new(ui_event_receiver, &sequencer);
            let secure_input_source = super::engine::funnel::secure_input::SecureInputSource::new(
                secure_input_receiver,
                &sequencer,
            );
            let mut sources: Vec<&dyn espanso_engine::funnel::Source> =
                vec![&detect_source, &exit_source, &ui_source, &ipc_event_source];
            if cfg!(target_os = "macos") {
                sources.push(&secure_input_source);
            }
            let funnel = espanso_engine::funnel::default(&sources);

            let rolling_matcher = RollingMatcherAdapter::new(
                &match_converter.get_rolling_matches(),
                RollingMatcherAdapterOptions {
                    char_word_separators: config_manager.default().word_separators(),
                },
            );
            let regex_matcher = RegexMatcherAdapter::new(
                &match_converter.get_regex_matches(),
                &RegexMatcherAdapterOptions {
                    max_buffer_size: default_config.max_regex_buffer_size(),
                },
            );
            let matchers: Vec<
                &dyn espanso_engine::process::Matcher<
                    super::engine::process::middleware::matcher::MatcherState,
                >,
            > = vec![&rolling_matcher, &regex_matcher];
            let selector = MatchSelectorAdapter::new(&modulo_search_ui, &combined_match_cache);
            let multiplexer = MultiplexAdapter::new(&combined_match_cache, &*context);

            let injector = espanso_inject::get_injector(InjectorCreationOptions {
                use_evdev: use_evdev_backend,
                keyboard_state_provider: key_state_store
                    .map(|store| Box::new(store) as Box<dyn KeyboardStateProvider>),
                evdev_keyboard_rmlvo: keyboard_layout_util::generate_inject_rmlvo(
                    &*config_manager.default(),
                ),
                ..Default::default()
            })
            .expect("failed to initialize injector module"); // TODO: handle the options
            let clipboard = espanso_clipboard::get_clipboard(ClipboardOptions::default())
                .expect("failed to initialize clipboard module"); // TODO: handle options

            let clipboard_adapter = ClipboardAdapter::new(&*clipboard, &config_manager);
            let clipboard_extension =
                espanso_render::extension::clipboard::ClipboardExtension::new(&clipboard_adapter);
            let locale_provider = espanso_render::extension::date::DefaultLocaleProvider::new();
            let date_extension =
                espanso_render::extension::date::DateExtension::new(&locale_provider);
            let echo_extension = espanso_render::extension::echo::EchoExtension::new();
            let random_extension = espanso_render::extension::random::RandomExtension::new();
            let home_path = dirs::home_dir().expect("unable to obtain home dir path");
            let script_extension = espanso_render::extension::script::ScriptExtension::new(
                &paths.config,
                &home_path,
                &paths.packages,
            );
            let shell_extension =
                espanso_render::extension::shell::ShellExtension::new(&paths.config);
            let form_adapter = FormProviderAdapter::new(&modulo_form_ui);
            let form_extension = espanso_render::extension::form::FormExtension::new(&form_adapter);
            let choice_adapter = ChoiceSelectorAdapter::new(&modulo_search_ui);
            let choice_extension =
                espanso_render::extension::choice::ChoiceExtension::new(&choice_adapter);
            let renderer = espanso_render::create(vec![
                &clipboard_extension,
                &date_extension,
                &echo_extension,
                &random_extension,
                &script_extension,
                &shell_extension,
                &form_extension,
                &choice_extension,
            ]);
            let renderer_adapter = RendererAdapter::new(&match_cache, &config_manager, &renderer);
            let path_provider = PathProviderAdapter::new(&paths);
            let config_path_provider = ConfigPathProviderAdapter::new(&paths);

            let disable_options =
                process::middleware::disable::extract_disable_options(&*config_manager.default());

            let notification_manager = NotificationManager::new(&*ui_remote, default_config);

            let mut processor = espanso_engine::process::default(
                &matchers,
                &config_manager,
                &selector,
                &multiplexer,
                &renderer_adapter,
                &match_cache,
                &modifier_state_store,
                &sequencer,
                &path_provider,
                &config_path_provider,
                disable_options,
                &config_manager,
                &combined_match_cache,
                &config_manager,
                &config_manager,
                &modifier_state_store,
                &combined_match_cache,
                &notification_manager,
                &config_manager,
            );

            let event_injector = EventInjectorAdapter::new(&*injector, &config_manager);
            let clipboard_injector =
                ClipboardInjectorAdapter::new(&*injector, &*clipboard, &config_manager);
            let key_injector = KeyInjectorAdapter::new(&*injector, &config_manager);
            let context_menu_adapter = ContextMenuHandlerAdapter::new(&*ui_remote);
            let icon_adapter = IconHandlerAdapter::new(&*ui_remote);
            let secure_input_adapter = SecureInputManagerAdapter::new();
            let text_ui_adapter = TextUIHandlerAdapter::new(&modulo_text_ui, &paths);
            let dispatcher = espanso_engine::dispatch::default(
                &event_injector,
                &clipboard_injector,
                &config_manager,
                &key_injector,
                &clipboard_injector,
                &clipboard_injector,
                &context_menu_adapter,
                &icon_adapter,
                &secure_input_adapter,
                &text_ui_adapter,
            );

            // Disable previously granted linux capabilities if not needed anymore
            if has_granted_capabilities {
                if let Err(err) = crate::capabilities::clear_capabilities() {
                    error!("unable to revoke linux capabilities: {err}");
                }
            }

            let mut welcome_handle = None;
            match start_reason.as_deref() {
                Some(flag) if flag == WORKER_START_REASON_CONFIG_CHANGED => {
                    notification_manager.notify_config_reloaded(false);
                }
                Some(flag) if flag == WORKER_START_REASON_MANUAL => {
                    notification_manager.notify_config_reloaded(true);
                }
                Some(flag) if flag == WORKER_START_REASON_KEYBOARD_LAYOUT_CHANGED => {
                    notification_manager.notify_keyboard_layout_reloaded();
                }
                _ => {
                    notification_manager.notify_start();

                    if !preferences.has_displayed_welcome() {
                        welcome_handle = super::ui::welcome::show_welcome_screen();
                        preferences.set_has_displayed_welcome(true);
                    }
                }
            }

            let mut engine = espanso_engine::Engine::new(&funnel, &mut processor, &dispatcher);
            let exit_mode = engine.run();
            if let Some(mut handle) = welcome_handle {
                handle.wait().expect("welcome screen died");
            };

            info!("engine eventloop has terminated, propagating exit event...");
            ui_remote.exit();

            exit_mode
        })?;

    Ok(handle)
}

fn grant_linux_capabilities(use_evdev_backend: bool) -> bool {
    if use_evdev_backend {
        if crate::capabilities::can_use_capabilities() {
            debug!("using linux capabilities to grant permissions needed by EVDEV backend");
            if let Err(err) = crate::capabilities::grant_capabilities() {
                error!("unable to grant CAP_DAC_OVERRIDE capability: {err}");
                false
            } else {
                debug!("successfully granted permissions using capabilities");
                true
            }
        } else {
            warn!("EVDEV backend is being used, but without enabling linux capabilities.");
            warn!("  Although you CAN run espanso EVDEV backend as root, it's not recommended due");
            warn!(
        "  to security reasons. Espanso supports linux capabilities to limit the attack surface"
      );
            warn!(
                "  area by only leveraging on the CAP_DAC_OVERRIDE capability (needed to work with"
            );
            warn!(
                "  /dev/input/* devices to detect and inject text) and disabling it as soon as the"
            );
            warn!("  initial setup is completed.");
            false
        }
    } else {
        false
    }
}
